Pulp beater



- Dec. 14, 19.43 w; MLNASH PULP HEATER Fiied Dec. 20, 1941 3Sheets-Sheet 2 Patented Dec. 14, 1943 PULP BEATER William M. Nash,Neenah, Wis., assignor of onei'ourth to Roy A. Nash, Bronxville, N. Y.,oncfourth to Mary Nash Jones, and one-fourth to Marie Duvall Nash, bothof Neenah,'Wis.; Marie Draper Nash administratrix of said William M.

Nash, deceased Application December 20, 1941, Serial No. 423,776

13 Claims.

This invention relates to improvements in a pulp beater and refersparticularlyto a rotary type of pulp beater so constructed as tothoroughly beat and wet the fibres and yet not unduly cut or shorten thelength of the fibres.

In so-called target beating, fibres in aqueous suspension are-thrownwith relativelyhigh velocity into contact with a stationary fiatsurface, known as the target. The impact of the fibres upon the targettends to bruise said fibres which is conducive to the wetting or pulpingof the fibres. In the usual Hollander beater this principle is employedsince the fibres are thrown into contact with the backfall, which inthis instance constitutes the target.

In my invention an improved application of the target principlevofbeating is employed, in that the target is in movement, as well as thefibres, during impact. In addition, in one cycle of circulation of thepulp instead of one dashing or throwing of the pulp being accomplished.the pulp is thrown into contact with a plurality of targets-and thepulping operation is thereby accelerated without in anywise resorting tosuch violent beating as to cut or unduly shorten the fibres.

Briefly described, my invention comprises a vat or tub, the interior ofwhich is separated longitudinally. by a midfeather or. midrib. Adjacenteach end of the midfeather a vertical shaft is positioned which carriessets of oppositely inclined rotors, the latter being so constructed asto cause an axial movement of the pulp along the shafts and asimultaneous circulating movement of the pulp around the midfeather.Each rotor simultaneously acts as a velocity-imparting agent and atarget whereby the pulp, is thrown from one rotor to the next adjacentrotor which, at this phase of the operation, acts as a target. I g

The objects and advantages of 'my invention will be more fullyappreciated from the accompanying drawings and following detaileddescription.

In the drawings,

Fig. -1' is a side elevational view, parts being broken'away; and partsbeing shown in section of my'improv'ed' beater.

Fig. 2 is a longitudinal sectional view of the vat or tub with therotors removed.

Fig. 3 is a top sectional view of the tub illustrating particularly themidfeather.

Fig. 4 is a transverse sectional view taken on line 4-4 of Fig. 2.

Fig. 5 is an enlarged face view of one of the rotors.

Fig. 6 is an elevaticnal view, parts being shown in section along line8-6 of Fig. 5, of the manner inwhich the rotors are mounted upon thedriving shaft.

' Fig. '7 is adetailed sectional view of one of the rotor ribs, taken online 1-1 of Fig. 6.

Fig. 8 is a detailed sectional view taken on line 8-8 of Fig. 5.

.Fig. 9 is a fragmentary face view of a modified form of rotor having aroughened surface.

Fig. 10 is a sectional view taken on line IIII0 of Fig. 9. I I

Referring in detail to the drawings, I indicates a vat or tub which hasa substantially oval crosssection. The vat I comprises lateral wa l 2, atop 3 and bottom 4, the lateral wall 2 being carried upon the bottom. Awall 5 which may be formed integral with, or be rigidly secured to, thebottom 4 may extend upwardly therefrom, and is adapted to divide the tubinto two longitudinal compartments 6 and- I. A recess 8 is'provided inthe bottom 4 adjacent each of the ends thereof, said recesses beingclosed by plates 9. As will be hereinafter more fully described, the,recesses 8 are adapted for the reception of thrust bearings l0. Thebottom portion of the compartment 6 slopes in one directionlongitudinally of the compartment and the bottom of compartment 1 slopesin the opposite direction, as shown best at H and I2 respectively inFig. 2.

Vertical shafts I3 and I4 are carried adjacent opposite ends of the tubor'yat I by the thrust bearings Ill, said shafts being journalledadja-.-

cent their upper ends in bearings I5 carried by the top 3. Exteriorly ofthe vat, a bevel gear I6 is keyed to shaft I4 and, similarly, a bevelgear I1 is keyed to shaft I3. Bearings I8 and I9 are mounted in spacedrelation upon the upper surface of top 3 and a shaft 20 is journalled insaid bearings. of shaft 20 and meshes with bevel gear I6 to drive shaftI4, and a bevel gear 22 is keyed to an intermediate portion of shaft 20which meshes with gears I I to drive shaft 13, both shafts being drivenin the same angular direction.

A pulley 23 is mounted on shaft 20 adjacent its opposite end and isdriven by belts 24 which are trained around pulley 25 of an electricmotor 26 which may be suitably mounted adjacent the tub I.

A plurality of rotors 21 are mounted upon each shaft I3 and 4 within thetub I. Each rotor 21 comprises a hub 28 provided'interiorly A bevel gear2| is keyed to the end with a keyway 29. Each shaft l3 and I4 is alsoprovided with a keyway, as shown at 30 in Fig. 6 whereby the rotors maybe keyed to the respective shafts. A disc 3| i formed integral with eachhub 23, said disc being disposed at an oblique angle to the axis of thehub. Each disc is provided with four relatively large cir cularapertures 32 which are angularly spaced from each other about 90. Thedefining edges 33 of said apertures are feathered or tapered for apurpose to be hereinafter more fully described.

Each disc carries a pair of radially disposed ribs 34 on each face andadiametrically opposite pair of radially disposed rib 25 upon theopposite face, the ribs on each face being disposed about 90 from eachother.

The discs 2'! are mounted in sets upon each shaft l3 and I4, that is, aplurality of discs adjacent one end of each of the shaft comprising oneset 36 all have their planes substantially parallel. A plurality ofdiscs mounted adjacent the opposite end of each shaft comprising a set.31 have their planes inclined at an oblique angle to the planes of thediscs constituting the first-mentioned set. My invention contemplatesany number of sets 36 and 31 of discs 21 upon each shaft, adjacent setsbeing inclined at oblique angles to each other. My invention alsocontemplates two or more discs 2'! as constituting each set.

In mounting the discs 21 upon shafts l3 and I4, a sleeve 38circumscribing each shaft is adapted to space the discs from the bottomof the tub. The discs of each set are then keyed to the shafts in such amanner that the ribs 35 are opposite a flat portion 39 upon the nextadjacent disc, and the ribs 34 are disposed opposite a flat portion 40of the next adjacent disc.

In operation, the tub I is substantially filled with fibres in'aqueoussusp nsion and the motor 26 is 'set in motion. Both shafts 13 and I4 3are rotated in the same angular direction thereby rotating the discs 21.The rotation of the discs adjacent each end of the tub causes motion ofthe body of pulp in the direction indicated by the arrowsin Fig. 3, thatis, the pulp flows in opposite directions on opposite sides of themidfeather; The translatory speed of the pulp from end to end of the tubis relatively slow compared to the peripheral speed of the discs and maybe described as a migratory motion. This, of course, results from thefact that the discs are not designed or constructed to function as pumpvanes and a positive flow of the pulp 'past the midfeather is notcontemplated. However. the presence of the ribs 34 and 35 upon the discsand the serrations or teeth 3| upon the periphery of the discs,- causethe discs to exert a mild propelling motion upon the pulp.

The inclination of the discs with respect to their axes of rotat on andalso the contours of the discs produce a motion of the pulp which,insofar as the beating of the pulp is concerned. is of more importancethan the migratory motion of the pulp around the midfeather.

The fact that the planes of the discs are obliquely inclined tothe'shafts l3 and I4. during rotation of the shafts the discs wobble,that is, with respect to a fixed plane outside the discs, the end wallsof the tub, for instance, the discs vibralte in a direction parallel tothe shafts l3 and 4.

To analyze the motion of the pulp in the end beater sections of the tub,attention is directed to that portion of pulp which is temporarilyconfined between two adjacent discs of one of the sets 36 or 31. Thediscs rotate at a predetermined rate of speed. However, th pulptemporarily carried between two discs does not move circumferential atthe same speed as the discs. The circumferential speed of the pulp as amatter of fact is relatively slower than that of the discs. there isslippage between the discs and that increment of pulp temporarilyconfined between adjacent discs, the wobbling motion of the discs tendsto oscillate this increment of pulp in a direction parallel to the shaftupon which the discs are mounted.

In oscillating the pulp, the pulp is moved by the face of one disctoward the face of an adjacent disc. Due to the inertia of the pulpincrement the pressure of the pulp adjacent the first-mentioned face isgreater than that upon the last-mentioned face. However, when the pulpduring the oscillating motion has reached the end of the throw of theoscillation, the pressure relationship reverse and the increment of pulpis thrown abruptly into contact with the last mentioned face. Theserapid impacts of the pulp increments throughout all of the disc setsaccomplishes a beating of the pulp in accordance with the principle oftarget beating.

The ribs 34 and 35 upon the discs intensify the throwing of the pulpfrom one face to the other since the ribs, during rotation of the discs,exert a component of force upon the pulp tending to throw it toward theopposite flat face of the adjacent disc.

By the provision of the apertures 32 in the discs, the forces which tendto move the pulp increments in an oscillating manner, also tend to causea portion of the pulp to extrude through said apertures from between onepair of discs to between the next adjacent pair of discs. In addition, ashearing action is also exerted upon the pulp in passing through saidapertures.

It is to be understood, of course, that I do not wish to be limited tothe above described hypothesis or theory of operation of my device,since, whatever the action which takes place, a well hydrated pulp canbe obtained in the use of my device; a pulp in which the desired longfibre length is preserved.

It will be noted that the floor of the tub is tapered, as shownat II andI2 in Fig. 2, the floor rising in the direction of movement .of thepulp. In addition, the. ends of the midfeather 5 are flared outwardly inthe line of travel of the pulp from the compartments 6 and 1 a greaterdistance than they are flared in the direction of passage of the pulpfrom the beating zones to the zones 6 and I, as shown best at 4| and 42in Fig. 3. The effect of so tapering the floor and flaring the ends 4|and 42 of the midfeather is to have a greater pulp density in thecompartmentsfi and 1 than in the beater sections since a back pressureis built up at the entrances to the beater sections.

A drain pipe 43 connects into the bottom 4 whereby the beaten pulp maybewithdrawn, a suitable valve, pipe. I

Referring particularly to Figs. 9 and 10, a slight modification of rotoris illustrated. The rotor 21' in all essential details is the same asrotors 21 except that a roughened surface 44 is provided.

One mannerin which such a surface can be Consequently, in view of thefact that not shown, being provided in said formed is to line the insideof the mold in which the metal is poured to form the rotor with amixture of carborundum and a binder. carborundum particles of a grainsize of about '76 may be mixed with Kordek, (a starch compound normallyused in preparing molding cores) molasses and water, the mixture beingspread on the inside of the mold. After the metal has been pouredthecarborundum will be firmly embedded in the surface of the rotor, asshown best at 45 in Figs. 9 and 10.- Of course, any desired manner ofroughening the surface of the rotor is contemplated.

It is to be understood that my invention contemplates that all or noneof the rotors may be of the roughened surface type or any desired numberof the rotors may be rough or smooth. It has been found that under someconditions improved results can be obtained in employing one or moreroughened surface rotors 21'.

I claim as my invention:

1. A pulp beater which comprises in combination a tub, a plurality ofsubstantially vertical beaters disposed in spaced apart position in saidtub. a partition extending between adjacent beat- Y era to providecompartments in said tub through which pulp flows from one beater to anadjacent beater, each of said heaters comprising a vertical shaft, and aplurality of beater discs mounted upon said sheets with their planesobliquely inclined to the axes of said shafts, and means for rotatingsaid shafts to circulate said pulp through said compartments.

2. A pulp beater which comprises in combination a tub, a plurality ofsubstantially vertical beaters disposed in spaced apart position in saidtub, a partition extending between adjacent beaters to providecompartments in said beater, each of said beaters comprising a verticalshaft, and a plurality of beater discs mounted upon each of said shafts,said beater discs being arranged in sets upon each shaft, each setcomprising a plurality of relatively closely spaced discsdisposed withtheir planes substantially parallel to each other and obliquely inclinedto the axis of the shaft upon which they are mounted, and means forrotating said shafts to circulate said pulp through the compartments.

3. A pulp beater which comprises in combination a tub, a plurality ofsubstantially vertical heaters disposed in spaced apart position in saidtub, a partition extending between adjacent beaters to providecompartments in said beater, each ed to be disposedsubstantialiyvertically in a For example,

beater tub, a plurality of beater disc mounted said shaft, said discsbeing arranged in sets upon said shaft, each set comprising a pluralityof beater discs, the discs comprising each set being I disposedobliquely to the axis of said shaft and being disposed with the planesof the discs substantially parallel, and the discs of adjacent setsbeing inclined oppositely to each other, ribs extending from theopposite faces of each disc, the ribs of one disc being disposedopposite a fiat portion of the next adjacent disc.

6. A pulp beater unit comprising a shaft adapted to be disposedsubstantially vertically in a heater tub, a plurality of beater discsmounted upon said shaft, said discs being arranged in sets upon saidshaft, each set comprising a plurality of beater discs, the discscomprising each set being disposed obliquely to the axis of said shaftand being disposed with the planes of the discs substantially parallel,and the discs of adjacent of said beaters comprising a vertical shaft, aplu- -rality of beater discs mounted upon each of said shafts, saidbeater discs being arranged in sets upon each shaft, each set comprisinga plurality of relatively closely spaced discs disposed with theirplanes substantially parallel to each other and obliquely inclined tothe axis of the shaft upon which they are mounted, adjacent sets ofdiscsupon each shaft being inclinedin opposite directions, and means forrotating said shafts to circulate said pulp through the compartments.

4. A pulp beater unit comprising a shaft adapted to be disposedsubstantially vertically in a beater tub, a plurality of beater discsmounted upon said shaft, said discs being arranged in sets sets beinginclined oppositely to each other, ribs extending from the oppositefacesof each disc, the ribs of one disc being disposed opposite aflat portionor the next adjacent disc, each of said discs being provided with anaperture whereby pulp may pass from between two adjacent discs throughsaid apertures to the area between the next two adjacent discs.

7. A pulp beater disc which comprises a hub adapted to embrace a shaft,a disc carried upon said hub with its plane disposed obliquely to theaxis'of said hub, a rib carried on, and extending from one face of thedisc, a rib carried on, and extending from the opposite face of thedisc, said ribs being positioned on said discs on opposite sides of saidshaft.

8. A pulp beater disc which comprises a hub adapted to embrace a shaft,a disc carried upon said hub With its plane disposed obliquely to theaxis of said hub, a rib carried on, and extending from one face of thedisc, a rib carried on, and extending from the opposite face of thedisc, said ribs being positioned on said discs on opposite sides of saidshaft, the face of said disc opposite the face which carries a'rib onthe same side of the hub being fiat.-

. 9. A pulp beater disc which comprises a hub adapted to embrace ashaft, a disc carried upon said hub with its plane disposed obliquely tothe axis of said hub, a pair of ribs carried on, and extending from oneface of the disc, said ribs being spaced approximately ninety degreesfrom each other; a pair of ribs carried on, and ex"- tending from theopposite face of the disc, said ribs being spaced approximately ninetydegrees .from each other, the ribs on one face of the disc .beingdisposed on the opposite side of the hub from the ribs on the oppositeface.

10. A pulp beater disc which comprises a hub adapted to embrace a shaft,a disc carried upon said hub with its plane disposed obliquely to theaxis of said hub, a pair of ribs carried on, and extending from one faceof thedisc, said ribs being spaced approximately ninety degrees fromeach other, a pair of ribs carried on, and extending from the oppositeface of the disc, said ribs being spaced approximately ninety degreesfrom each other, the ribs on' one face of the disc being disposed on theopposite side of the hub from the ribs on the opposite face, said discbeing provided with an aperture connecting one face to the other.

11. A pulp beater disc which comprises a hub adapted to embrace a shaft,a disc carried upon said hub with its plane disposed obliquely to theaxis of said hub, a ribcarried on, and extending from each of theopposite faces of the disc, said ribs being positioned on said discs onopposite sides of said shaft, both faces of said disc being rou hened.

12. A pulp beater disc which comprises a hub adapted to embrace a shaft,a disccarried upon said hub with its plane disposed obliquely to theaxis of said hub, a rib carried on and extending from one face of thedisc, a rib carried on, and extending from the opposite face of thedisc, said ribs being positioned on said discs on 13. A pulp beaterwhich comprises in combination a tub, a plurality of substantiallyvertical beaters disposed in spaced apart position in said oppositesides of said shaft, and carborundum 15 said compartments.

particles being carried on both faces of said disc.

WILLIAM M. NASH.

